1. Technical Field
The present invention generally relates to a method of controlling a compressor for a refrigerator. More particularly, it relates to a method for detecting a malfunction of the compressor and a connection trouble between the compressor and an inverter circuitry during initial driving of the compressor in a refrigerator.
2. Background Art
Inverters and compressors driven by the inverter have been widely used in refrigerators. Typically, a controller controls the inverter to drive a D.C. motor of the compressor. Also the controller detects a reverse electromotive force (a reverse induction voltage) of the D.C. motor and evaluates a rotation position of a rotor of the D.C. motor. Accordingly, the controller controls the inverter to drive the D.C. motor by using the rotation position of the rotor as a feedback signal.
The controller, however, may fail to control the inverter because of a malfunction of the compressor and a disconnection between the compressor and the inverter. Even if the controller receives the reverse electromotive force and detects the position of the rotor of the D.C. motor, the controller cannot control the inverter and the D.C. motor precisely. This is because the controller merely uses the position of the rotor from the reverse electromotive force for adjusting the inverter. The controller does not use the position of the rotor for detecting the malfunction of the compressor and the disconnection between the compressor and the inverter. Accordingly, the refrigerator cannot be controlled effectively. Moreover, the motor and the inverter may be overloaded or overheated because the controller continues to control the inverter to drive the motor. Furthermore the foodstuffs may be spoiled if rotation speed of the motor is not in a normal mode, or the motor is turned off. Therefore, I have founded that a new method is needed to detect the malfunction of the compressor and a disconnection between the compressor and the inverter in order to avoid a malfunction of the controller and to improve the refrigerator's ability.